1. Field of the Invention
The present invention relates to a device for adjusting height of a shoulder anchor which forms, for example, a seat belt apparatus of a vehicle.
2. Description of the Related Art
In a seat belt apparatus for constraining with a long belt-shaped webbing belt a body of a vehicle occupant sitting on a seat, a winding device for winding the webbing belt is disposed in the vicinity of a lower end portion of a center pillar of the vehicle. The webbing belt is pulled upward along the center pillar and turned down as it passes through a shoulder anchor mounted in the vicinity of an upper end portion of the center pillar. A distal end portion of the webbing belt is anchored to an anchor plate provided in the vicinity of a seat portion of the seat.
The webbing belt passes through a tongue between the anchor plate and the shoulder anchor. The seat belt apparatus is constituted in such a manner that the webbing belt is attached by the vehicle occupant gripping the tongue, pulling the webbing belt and causing the tongue to be held in a buckle device provided in the vicinity of the seat.
Of the devices and members which constitute the seat belt apparatus having the above constitution, the shoulder anchor can be formed to be slidable within a predetermined range along the center pillar with a device for adjusting height of a shoulder anchor, which device likewise forms a seat belt apparatus. As a consequence, a turning down position of the webbing belt can be adjusted.
The device for adjusting shoulder anchor height includes a plate-shaped guide rail secured to the vicinity of the upper end portion of the center pillar with a bolt or the like in a state in which the longitudinal direction of the guide rail runs substantially along the vertical direction of the vehicle, and a slider which is slidably attached along the longitudinal direction of the guide rail in a state in which the slider grips both end portions of the guide rail in the width direction thereof. The above shoulder anchor is anchored to this slider. The slider is provided with a cover and a lock pin is provided thereinside.
A plurality of lock holes are formed in the guide rail along the longitudinal direction thereof. An inner circumference portion of each lock hole restricts movement of the lock pin along a sliding direction as a result of entry of the lock pin, which projects from the slider, thereby restricting sliding of the slider. In other words, the height of the shoulder anchor can be adjusted by allowing the lock pin to enter into one of the plurality of lock holes.
Furthermore, in order to prevent generation of an impact sound, which is generated at a time of sliding of a main body of the slider or at a time of collision of the main body of the slider with the guide rail caused by vibrations generated by the running vehicle, and in order to prevent generation of a scraping sound, which is generated at a time of sliding movement of the lock pin on the guide rail, a sheet formed of synthetic resin material is attached to the guide rail.
Indentations are formed in the sheet in correspondence with the lock holes. The indentations enter the lock holes in a state in which the sheet is attached to the guide rail. A portion at an upper side of an inner circumference portion of each indentation serves as a guide portion. An end portion of the guide portion at an open side of the indentation is located substantially at the same position as a surface of the sheet. An opposite end portion of the guide portion serves as an inclined surface located substantially at the same position as an inner bottom portion of the indentation. In a state in which the lock pin enters the lock hole, when the main body of the slider is raised, the lock pin is guided by the guide portion. Thus, the lock pin is moved toward the surface side sheet. Thereafter, the lock pin slides on the surface of the sheet. Consequently, even in the state in which the lock pin has entered the lock hole, the slider can be raised. Movement of the slider is substantially limited only in a downward direction. (In a case wherein the device for adjusting the height of the shoulder anchor is to be lowered in the state in which the movement is limited, it is necessary to perform a releasing operation by depression of a button or the like which is separately provided.)
The device for adjusting shoulder anchor height has a structure in which a pin is formed on the sheet, the pin is heat welded to the guide rail in a state in which the pin passes through the guide rail, and the diameter is enlarged and caulked, thereby securing the sheet to the guide rail.
In such heat welding and caulking, time is required to heat the pin, and time is required for cooling after caulking, which reduces work efficiency and thereby constitutes a factor hindering reduction of manufacturing costs.
Also, because the sheet is formed of synthetic resin material, when the lock pin rides up on the guide portion, the guide portion is bent by a load from the lock pin. Thus, there is a possibility that the lock pin cannot be smoothly guided. In order to solve this problem, a tongue-like support piece extends from the inner circumference of the lock hole, and the guide portion is supported by this support piece.
However, if a gap occurs between the support piece and the guide portion after the sheet is assembled onto the guide rail, the guide portion will be bent by the lock pin load. Thus, in order not to form a gap of more than a predetermined size between the support piece and the guide portion, it is necessary to manufacture both the support piece and the guide portion with strict size control, which constitutes a factor hindering reduction of manufacturing costs.
Hence, in a slider and a sheet having a conventional structure, much remains to be improved in view of cost reduction.
In consideration of the above facts, an object of the present invention is to provide a device for adjusting shoulder anchor height, the device being provided with a buffer member such as a sheet or the like which effectively enables a reduction of manufacturing costs.
In a first aspect of the present invention, there is provided a device for adjusting shoulder anchor height of a seat belt assembly in a vehicle, the device comprises a guide member securable to a vehicle having a seat belt assembly with a shoulder anchor, a slider adapted for connection to the shoulder anchor, the slider being engaged with the guide member and slidable therealong, an engaging member attached to one of the slider and the guide member and engaging with the other of the slider and the guide member to thereby fix a position of the slider and the guide member relative to one another, a buffer member having a main body, the main body being mounted on said other of the slider and the guide member, and having an inclined surface with a lower side, the buffer member being interposed between the engaging member and the other of the slider and the guide member, and a reinforcing rib integrally provided at the main body on the lower side of an inclined surface portion which guides the engaging member in a direction opposite to an engaging direction of the engaging member when the slider moves.
In a second aspect of the present invention, there is provided a device for adjusting shoulder anchor height of a seat belt assembly in a vehicle, the device comprises a guide member securable to a vehicle having a seat belt assembly with a shoulder anchor, a slider adapted for connection to the shoulder anchor, the slider being engaged with the guide member and slidable therealong, an engaging member attached to the slider which engages with the guide member to thereby fix a position of the slider and the guide member relative to one another, a buffer member having a main body attached to the guide member and interposed between the engaging member and the guide member, the main body having an inclined surface portion with a lower side, reinforcing ribs integrally provided at the main body on the lower side of the inclined surface portion which guide the engaging member in a direction opposite to an engaging direction of the engaging member when the slider moves, and a recess portion provided continuously from the inclined surface for allowing the engaging member to enter thereinside for providing engagement, the engaging member urged toward the bottom surface of the recess portion of the main body by a spring.
In a third aspect of the present invention, there is provided a device for adjusting shoulder anchor height of a seat belt assembly in a vehicle, the device comprises a slider on which is mounted a shoulder anchor, a guide member for guiding the shoulder anchor, a lock pin in the slider, which lock pin engages with a lock hole which is formed along the longitudinal direction of the guide member, a buffer member which is disposed at the inner perimeter of the lock hole, a recess portion and an inclined surface portion which are provided on the buffer member, and a reinforcing section which is integrally provided with the buffer member on a lower surface of the inclined surface portion.
The device for adjusting shoulder anchor height having the above structure is provided with a guide portion corresponding to a lock hole into which the engaging portion enters. The engaging member is guided by the inclined surface of the guide member to leave the lock hole when the slider slides, as a result of the engaging member riding up on the inclined surface of the guide portion.
Here, because a rib section is formed on the guide portion, the guide portion does not bend when a load or the like from the engaging member acts on the guide portion. Consequently, the guide portion can maintain an original configuration, and the engaging member can be smoothly guided.
Moreover, because the rib section for reinforcing the guide portion is integrally formed at the guide portion, a gap is not formed, unlike a conventional guide member and support piece. Consequently, strict size control is not required for forming the buffer member and whichever of the slider and the guide rail the buffer member is attached to. Hence, the manufacturing cost of the device for adjusting shoulder anchor height can be reduced.